remove some words from string

[Rahul Dev]

hi folks, i have a variable in which some common words are stored and another variable in which a sentence is stored. I want to remove the common words from the sentence> Is there any way of doing this in PHP?

<?php
$common_words = "to, this, all, the, from";
$sentence = "I want to remove all the common words from this sentence";
?>

the final output should be:

"I remove common words sentence."

[trq]

str_replace.

[Rahul Dev]

str_replace.

when i use str_replace() i can't remove certain words correctly e.g my common_words contains the word "the" and if my sentence contians the word "they" then it would output "y"

<?php

$sentence  = "I want to remove all the common words from this sentence because they are irrelevant";
$common_words = array("to", "this", "all", "the", "from");

$newphrase = str_replace($common_words, "", $sentence);
echo $newphrase;
?>

[trq]

$common_words = array(" to ", " this ", " all ", " the ", " from ");

[Rahul Dev]

thanx for the help!